The radiation risk of patients undergoing invasive cardiology remains considerable and includes skin injuries and cancer. To date, submillisievert coronary angiography has not been considered feasible.

In 2011, we compared results from 100 consecutive patients undergoing elective coronary angiography using the latest-generation flat-panel angiography system (FPS) with results from examinations by the same operator using 106 historic controls with a conventional image-intensifier system (IIS) that was new in 2002.

The median patient exposure parameters were measured as follows: dose–area product (DAP) associated with radiographic cine acquisitions (DAP^R) and fluoroscopy (DAP^F) scenes, radiographic frames and runs, and cumulative exposure times for radiography and fluoroscopy. On the FPS as compared to the traditional IIS, radiographic detector entrance dose levels were reduced from 164 to 80 nGy/frame and pulse rates were lowered from 12.5/s to 7.5/s during radiography and from 25/s to 4/s during fluoroscopy. The cardiologist’s performance patterns remained comparable over the years: fluoroscopy time was constant and radiography time even slightly increased. Overall patient DAP decreased from 7.0 to 2.4 Gy × cm²; DAP^R, from 4.2 to 1.7 Gy × cm²; and DAP^F, from 2.8 to 0.6 Gy × cm². Time-adjusted DAP^R/s decreased from 436 to 130 mGy × cm² and DAP^F/s, from 21.6 to 4.4 mGy × cm². Cumulative patient skin dose with the FPS amounted to 67 mGy, and the median (interquartile range) of effective dose was 0.5 (0.3 … 0.7) mSv.

Consistent application of radiation-reducing techniques with the latest-generation flat-panel systems enables submillisievert coronary angiography in invasive cardiology.